This plugin adds link for the category feeds after post content.
Clifton's Lightbox implements a lightbox subscription form overlay. Features a title, list, call-to-action, and image or video.
Send SMS via wordpress
Subscription form for russian users of service E-mail Marketing (selling mailing)
Adds Feedburner Subscription Form at the end of post content.
WP FollowMe plugin allows you to add a twitter "Follow me" badge on your wordpress blog.
A Widget to add an Arrow newsletter subscription form .
This plugin generates a widget to add Google+ badge on your blog with 'Add to Circles' button.
Make it super easy for visitors to subscribe to your mailing list! Add a RuleMailer newsletter subscribe widget to your blog.
This plugin let the users to add your Google+ Page to their circle directly from your website.
This plugin lets you place a Facebook Subscribe Box on your WordPress blog as a widget.
Feedburner Counter shows the number of subscribers your feed has, even if the FeedBurner website is offline.
With this plug-in, blog owner will be able to "link" his Oempro account with WordPress and start accepting email list subscriptions.
Subscribe to Comments plugin has "subscribe without commenting" form, but you must edit your template to insert it. This plugin displays thi
Hallo Destra add social media icons in the theme wherever you want to display. Simple and looks luxurious.
A simple widgetized mailing list subscription form utilizing jQuery.
Widget show subscribe2 bar in any sidebar.
Adds MailChimp Subscribe Widget to Simple CRM
xCake Ads Lite allows you to add banners to your sidebar via a widget. Still in beta-testing mode (expect daily updates)
Email Alert subscribe form.
Add your blog to any browser! Get a bottom bar inviting users to subscribe to your website. It will add a custom RSS reader extension to their browser
Subscribe Remind will add a brief message at the bottom of each post inviting users to subscribe to your RSS feed or follow you on Twitter.
The Online Outbox plugin allows you to easily add a subscription form to your WordPress site, to grow your list of email subscribers of your Email New
Install Wikio buttons on your blog!
Automatically prompt subsription message to promote and make visitor subscribe your feed every they post a new comment
Sidebar widget to easy customize and display your subscribers buttons. All settings are available from Sidebar Widget Admin.
** Deprecated in BP 1.2. Use http://wordpress.org/extend/plugins/buddypress-group-email-subscription/ ** Gives users the ability to subscribe to email
Add a Subscribe to MadMimi Checkbox after the comment form
Add an iCal feed to your site for the Events Calendar plugin
Add a list of "Subscribe" links to your sidebar. Options include your blog and podcast feed, Twitter page, iTunes, Facebook Fan Page, Google Profiles